Injector



May 21, 1929. R. D. METCALE ET Al.v 1,713,772

INJECTOR Filed March 2, 1927 4 Sheets-Sheet l May 21, 1929. R. D. METCALFE ET AL 1,713,772

INJEQTOR Filed March 2, 1927 4 Sheets-Sheet 2,

v May 21, 1929- R. D. METCALFE ET AL 1,713,772

NJECTOR Filed March 2. 1927 4 Sheets-Sheet ESy Figz ,/ May 2l, 1929. R. D. MTCALFE ET AL INJECTOR 4 sheets-shewJ 4 Filed March 2, 1927 Figz Patented May Z1, 1929a RICHARD DAVID METCALFE AND JAMES CROXON METCALFE, GF ROMILEY, NEAR MANCHESTER, ENGLAND.

INJEGTOR.

Application led March 2, 192'?, Serial No. 172,152, and in Great Britain November 22, 1926.

This invention relates to exhaust steam injectors in which a supplementary supply of live steam is provided 'for increasing the delivery pressure and in which an alternative supply oi live steam throttled down to about atmospheric pressure is admitted when eX- haust steam is not available.

The object of our present invention is to providesimplified control arrangements for theinjector so as to obviate the necessity for several steam pipes between the control littingg' which may be on the front of the boiler and the injector' which is arranged at a low level so as to be beneath the water supply.

Uur invention comprises the incorporation in the injector itself oll the automatic control valves for the exhaust steam and water supplies and for providing a live steam supply to replace the exhaust steam when a supply of the latter is not available, the arrangement being such that onlyV a single steam supply pipe with a valve thereon is necessary to control the functioning of the injector.

Uur invention further comprises the provision ofautomatic means for ensuring that under normal conditions steamis supplied to the supplementary live steamk nozzle and water is admittedV to the injectorbefore the valve controlling the admission of exhaust steam to the injector is opened.

Referring to the accompanying sheets of explanatory drawin Figure 'l is a part elevation and part sectional elevation of an eXhaust injector' con* structed and arranged in one convenient manner in accordance with our invention.

Figure 2 is partly a plan view of the injector shown in Figure l and partly a sectional plan view on the line 2 2 of Figure 4l.

Figure 3 is a'sectional end elevation on the line 3 3 of Figure 2.

F igure 4 is a sectional elevation on the line 4&4 of Figure 2.

Figure 5 is a sectional elevation similar to Figure 3 but showing a modification. ,j

The same reference letters in the difieren views indicate the same parts. v

As illustratech the injector comprises an exhaust steam inlet o, a supplementary live steam inlet b with nozzle. c, and inlet cl for live steam throttled down toa low pressure to work the injector when exhaust steam is not available7 a water inlet e and a delivery outlet j".

Y allow steam to escape from between the valve The drivers control itting which is not shown and which may be mounted inany convenient position merely consists in a valve on a live steam pipe connected to the branch g of the injector. The steam entering` at g can pass direct to the supplementary live steam space E and the nozzle c. It can also pass by way of the passage 7a to the underside of the piston e' which in its raised position holds open the spring loaded valve j controlling the iow of water from the inlet branch e to the space around the steam inlet nozzle m. l.Vith the parts in the positions shown in F igure 3, steam from g can also pass into the space n beneath the valve 0 and if the steam pressure is sulicient to overcome the load of the spring` p upon said valve7 opens the latter and passes to the upper side of the piston q which is depressed andacting through the lever v ure l) opens the exhaust inlet valve s. The spring holds the valve s on its seat and returns the piston to its uppermost position when the steam pressure is removed from the piston. A leal; aperture n is provided to o o and the piston @when the live steam is cut oft by the seating; oi the valve @c on its seat Q/ and so allow the piston to rise under the action of the spring t.

Steam from the valve chest ol the engine supplyingexhaust steam to the injectorenters the automatic valve fitting' at o and loads the valve w so as to prevent the pressure of the live steam at gV 'from raising` the valve .fc from its lower seat which, as shown in Figure 3, it is seated upon. lf however, there is no steam pressure in the engine valve chest and therefore no exhaust steam available, the valve fr is allowed to rise and seat upon the upper seating surface y when it cuts oli` steam from the valve o but allows steam to pass downwardsthrougli the spaces e to the passage Z before referred to. A calibrated plug 6 restricts the rate or low of steam to (Z in order to reduce the steam pressureto the low amount desired. Y j

A valve 9 is provided on the atmospheric connection l0, the said valve serving to close said connection when there is steam pressure in the branch o and allowing air to enter such branch when there is no steam therein so as to prevent any pulsating action on the valve w such as would occur in the case of a Cil j rate at Which pressure builds up .above the Y steam control valve.

piston g so as to ensure that the valve s is not opened until thefwaterl valve '7' hasopened and steam is being delivered through the supplementary live steam nozzle c. Vile may provide Within the injector a valve for controlling the flovv of supplementary live steam to the nozzle c, and such valve may be controlled from a point adjacent tothe drivers steam control-valve. y

The operation ofv the arrangement is as follower- Y l Assuming that exhaust steam isfavailable and the driver Wishes to start the injector in the normal manner, he gradually opens his This allows steam to enter' at'g andV topass to the supplementary Y steam space Z1 and nozzle c and to the Water valve control fitting yshovvn in Figure 4 by way of the passage 7L whereupon Water is' admitted. to the injector. Owing to the pressure Vof the spring p on the valve 0, vthe latter is not able to open atV first but as the driver continues to move his control handle and open his steam valve further, the steam pressure isable to Aforce open such valve 0 and i tion of the Vchoke tube 0 is the same as that 4o so depress thepiston'g and openL the valve s which can now function normally. The funcof the valve o, namely, to delay the rateat which pressure builds up above the piston g and so the time of opening of the valve s. lf t-he supply of exhaust steam fails, the valve (Figure 3) Will cut off the supply of steam to the valve o which will then close and the valve S Will also close. Live steam will pass via the loiver seating of the valve x to the passage Z and take the place of the exhaust steam. vThe supplementary steam and the Water supply Will not be interfered with. y `It Will be seen that the valveo has a delaying action preventing the valves .being opened until the supplementary steam and Water supplies to the injector .have been es-A tablished.y Y V l Y By reason of the employment-,of one steamv pipe only between the control fitting and the injector and an ordinary type of steam valve as'su'ch control fitting, We simplify and im-` prove the exhaust injector installation.

We do not limit ourselves to `any particu-` lar arrangement of the injector nozzles.

What'we claim is a. j 1. An injector comprising a live stem inlet,

valve in the exhaust steam inlet and means to delay the ypassage of vsteam to said last named operating means afterthe Steam is supplied to said live steam inlet.

2. Aninjector as claimed in claim lin which the steam delaying means includes a spring loaded valve. i

3. An exhaust steam injector having a con- ,trol arrangement comprising a-'single live steam pipe, an automatic control valve to which said pipe leads, exhaust and VWater inlets, steam operated valves controlling the admission of exhaust steam and Water to the injector itself, meansoperated'vvith the Vliver steam for opening said valves, said automatic control valve controlling the admission of live-steam to the opening means for the valve controlling the admission of exhaustV steam and an automatic delaying means for retarding the time of opening of the'exhaust steam inlet valve relatively to the time of C admission of live steam and Waterto the inj ector. Y Y

Ll. In exhaust steam injectors, the improved control arrangement comprising a single live steam pipe with a valve thereon, an exhaust steam inlet controlling Valve controlled by live steam, an automatic control valve incorporated in the injector itself, controlling the admission of live steam to operate said controlling valvein said exhaust steam inlet and a delay valve for retarding the time of opening of the exhauststeam inlet relatively to the time of admission of live steam to the inj ector.

5. In exhaust steam injectors, thev improved control arrangement comprising a single steam pipe With av valve thereon, an exhaust steam inlet controlled by a live steam operated valve, an automatic control valve incorporated in the injector itself and delaying means for retarding the time of opening of the exhaust steam 'inlet valve relative to the time vof admission of live steam to` the inj ector.

6 In exhaust steam injectors, the'incorpol ration in theinjector of a fitting With a live steam supply connection thereto, a Water inlet, a live steam operated valve in said inlet, means to pass a ,steamY supply directly to the steam nozzle and to the means for operating the valve in the Water supply inlet, an exhaust lsteam inlet and a live steam operated valve y in said inlet, means for controlling the admis-V sion ofl steam to said live steam operated valve in said exhaust steam inlet, means for delaying the passage of steam to said operating' menne for the Valve in the exhaust steam inlet ,euch that during the no1-nml stm-ting op eration the live steam and Water Supplied to 5 the 'injector are operated before the exhaust steam inlet is opened.

7. An injector as claimed in claim 1 in which the delaying means is a loaded valve and there is provided a leak aperture between opposite sides of said valve. 10 In testimony whereof We have Signed our names to this speecaton.

RICHARD DAVID METCALFE. JAMES CROXGN METCALFE. 

